Acceleration:

Eric and I made a number of acceleration runs, but there were only three acceleration runs that made the cut. Unfortunately, what seemed to be Eric's best run wasn't recorded by the G-Tech since it took too long for him to stage his car. There was another pair of runs that didn't make it in there due to excessive wheelspin and a missed shift. All in all, however, Eric did very well for his first foray into the world of car flogging!

Eric's first run was slower than hoped with a 0-60mph time of 9.0 seconds and a 16.5 second quarter mile. However, after further review he had neglected to shut off the traction control, which strangled the the motor and dropped the RPMs to 1500 at launch. His second run was the fastest of the recorded ones, with a 0-60mph time of 8.1 seconds and a quarter mile in 15.9seconds @ 90mph! His last recorded run was slower due to a softer launch and a slow 2-3 shift.

Power:

The highest power output recorded today was 149bhp @ 5200-5400rpm, and his torque peak was about 180lb-ft @ 3800rpm. Using my correction worksheet, that calculates to about 184-187bhp. This is closest hit we've seen, since his engine is rated at 185bhp @ 5500rpm. Awesome! Eric's engine is unusual for a turbo since the power and torque curves are so flat. This particular flavor of Saab engine is called a "low pressure turbo" running a limited amount of boost, but the torque is rated at 207 lb-ft from 1800-3800rpm. Since we did not do a power run we didn't get a full RPM range power curve, but both the power graph and the wheelspin on demand make convincing arguments that Saab isn't exaggerating the unusually strong, low-end torque on their turbos.

Another interesting point was that normally I use my OBD2 logger to record the intake air temperature for the most accurate atmospheric corrections. I've noticed that with normally-aspirated engines the intake temperature can be elevated by 10-20 degrees over outside ambient temp due to the engine's heat. However, in Eric's case I could not use the intake temperatures it recorded because they were between 85 and 120 degrees, in spite of the ambient temp at 64 degrees! This is due to the turbo impeller heating up the intake air with the heat absorbed from the exhaust, even though Eric's engine does have an intercooler to remove some of that excess heat. This illustrates how effective turbos are at increasing power: in spite of bumping the intake air temperature up by 50-100%, the pressurization it was able to provide still forced more oxygen into the motor and produced a nice 30%+ boost in power over a normally aspirated engine.

Technique:

Welp, the first place for improvement in Eric's acceleration technique would be to moderate the wheelspin a bit. In spite of having about 1/3rd the displacement of Chad's tire smoke dispenser, Eric "Leadfoot" Hanson gave his best shot at reducing the tread depth of his tires as quickly as possible. :)

As you can see in the acceleration graphs, Eric's runs varied by about eight-tenths of a second in the quarter mile. Most of these differences comes from the differences in his launch technique. The first run was hobbled by the traction control system which dropped the engine to 1500rpm. The second run was the best with an excellent job of modulating wheelspin to keep the RPMs right on the power peak. The third run was a flat-to-the-floor wheelspin fest that cemented Eric's place in the Burnout Gallery.

When looking at the shift points for all the runs, you can see Eric shifted from 2nd to 3rd at about 5400rpm in the first run, and about 6000rpm in later runs. When you look at the inset acceleration graph, you can see the acceleration drops off quicker in the first run, but also comes back quicker. That's because the engine was still making very good power at 5400rpm, and the shift fell right on the torque peak. In this case my advice of 6000rpm shifts was a bit too high for the 2nd-3rd shift; a better choice would probably be about 5600-5700rpm.

The final suggestion I have would be to try and speed up the gearshifts, and keep on the throttle a bit as well. As I mentioned earlier, you can see the differences in acceleration between the 2nd-3rd shifts. The loss of boost and flat acceleration in the last run cost a couple tenths in the quarter mile. As always, practice makes perfect!

Corrections and Other Factors:

Since Eric had one run that was significantly better than the others due to traction control and shift issues, I've used it to calculate the normalized data. Here is the data from the best run in original and corrected form:

	Recorded Data	Corrected Data
Best Run	0-1/4 mile in 15.9 secs @ 90mph	0-1/4 mile in 15.6 secs @ 92mph